Metalizing Polymer & Composite Components in the Aerospace Industry
The universal goal of aerospace engineers is the reduction of weight in a vehicle or structure. This is why the use of polymer and composites has cautiously increased since WWII as empirical evidence of their strength and durability has given manufacturers the confidence to deploy more.
The light weight of polymers components, 20-30% less than that of metals, as an example, has a direct impact on fuel efficiency and useful loads in aircraft, but there are many other benefits: increased corrosion resistance, reduced thermal conductivity, less thermal expansion. On the other hand, the natural properties of most polymers and composites, namely that they are highly dielectric, requires that they be enhanced with conductive metal treatments.
For example, multi-pin electrical connectors are increasingly being molded with such materials as carbon fiber filled PEEK, for their lightness and corrosion resistance, however thin layers of copper and nickel are plated on these connectors to give them grounding and lightning strike protection.
Another example: Composite wing and control surface structures do not naturally dissipate lightning strike energy, so conductive metal meshes usually copper, are added during the carbon fiber and resin lay-up process.
SAT specializes in the metal plating of these high performance polymers being used by the aerospace industry. PEEK, PAEK, PEKK, PI carbon fiber and Ultem are some of the key materials on which we plate coppers, nickels, golds, silvers, and chromes. We can process 3D printed components, injection molded, films, fibers, woven and non-woven fabrics. Typical applications are for RFI/EMI shielding, conductivity/grounding, abrasion resistance, lubricity, and UV and chemical protection.
Plating Rapid/3D Parts
The strength and durability of rapid parts is increasing with advances in material and printer technology, with some parts even having FAA-PMA approval for use in non-structural aircraft applications.
Appearance plating – Even the best rapid techniques still produce parts with a less-than-smooth surface finish. Those customers who seek a mirror finish of chrome are disappointed to learn that standard platings are too thin to fill the voids and ridges formed in the printing process. A satin finish results, but this often satisfies aesthetic requirements for many customers. Those who insist on mirror finishes must apply and hand sand multiple layers of fillers until the desired finish is achieved. Only at that point can the part be plated with a mirror finish. This preparation is very labor intensive, with highly inconsistent results. There are several companies working on automated post-printer finishing techniques, some employing heat, some solvents, some bulk mechanical abrasion. To our knowledge, while these processes definitely reduce roughness, they still fall short of creating a truly smooth surface.
Functional plating – Platings can serve to physically strengthen rapid parts, add RFI/EMI shielding, and abrasion resistance, among other features. SAT can plate most of the commonly used FDM and SLS resins, including SLA-type UV cured acrylic resins.